Transmission In A Guard Band Of A RAT

ABSTRACT

A radio node is configured to transmit, within a guard band of a first radio access technology (RAT), a radio signal according to a second RAT. The radio node determines, based on a channel bandwidth of the first RAT, one or more transmit parameters for transmission of the radio signal according to the second RAT within the guard band of the first RAT, for transmission of the radio signal to comply with emission limits for the first RAT. The one or more transmit parameters include a frequency position of the radio signal within the guard band for the first RAT. The radio node also configures the radio node with the one or more transmit parameters for transmitting the radio signal according to the second RAT within the guard band of the first RAT.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/301,874, filed Nov. 15, 2018, which is a national stageapplication of PCT/SE2017/050554, which was filed on May 23, 2017, andclaims benefit of U.S. Provisional Patent Application Ser. No.62/340,337 filed May 23, 2016 and U.S. Provisional Patent ApplicationSer. No. 62/341,582 filed May 25, 2016, the entire contents of each ofwhich are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to the field of communications,and in particular to transmission in a guard band of a radio accesstechnology.

BACKGROUND E-UTRA Downlink and Uplink Carrier Frequencies

Evolved universal terrestrial radio access (E-UTRA) uses orthogonalfrequency division multiplexing (OFDM) in downlink (DL) transmission andsingle carrier frequency division multiple access (SC-FDMA) in theuplink (UL). The center frequency of the DL bandwidth and the ULbandwidth is called carrier frequency. The subcarrier spacing for bothDL and the UL is equal to 15 kHz.

In order to limit the magnitude of the signal which causes inefficiencyin the digital to analog (D/A) and analog to digital (A/D) converters,the direct current (DC) subcarrier in the DL is usually not used fortransmission and is set to zero. In the baseband signal this subcarriercorresponds to frequency zero, which means a DC component in thebaseband signal.

To avoid the similar problem in the UL, the subcarriers are shifter by7.5 kHz to avoid transmission on the center frequency and also to savethe number of subcarriers. FIG. 1A for example illustrates subcarrierarrangements in the DL and UL in the legacy E-UTRA standard.

The carrier frequency in the uplink and downlink is designated by theE-UTRA Absolute Radio Frequency Channel Number (EARFCN) in the range0-262143. The relation between EARFCN and the carrier frequency in MHzfor the downlink is given by the following equation, where F_(DL_low)and N_(Offs-DL) are given in Table 5.7.3-1 of 3GPP technicalspecifications 36.101 and 36.104 (as shown in FIGS. 1B-1C), and N_(DL)is the downlink EARFCN.

F _(DL) =F _(DL_low)+0.1(N _(DL) −N _(Offs-DL))

The relation between EARFCN and the carrier frequency in MHz for theuplink is given by the following equation where F_(UL_low) andN_(Offs-UL) are given in Table 5.7.3-1 of 3GPP technical specifications36.101 and 36.104, and N_(u)s is the uplink EARFCN.

F _(UL) =F _(UL_low)+0.1(N _(UL) −N _(Offs-UL))

E-UTRA Out of Band Emission

The out of band emissions are unwanted emissions immediately outside theassigned channel bandwidth resulting from the modulation process andnon-linearity in the transmitter but excluding spurious emissions. Thisout of band emission limit is specified in terms of a spectrum emissionmask and an Adjacent Channel Leakage power Ratio (ACLR).

The spectrum emission mask applies to frequencies (Δf_(OOB)) startingfrom the ± edge of the assigned E-UTRA channel bandwidth. As an example,for E-UTRA user equipment (UE) the emission should not exceed the levelsspecified in Table 1 shown in FIG. 2 for the specified channelbandwidth.

Narrow Band Internet of Things (NB-IoT)

In GERAN #62, a study item on “Cellular System Support for Ultra LowComplexity and Low Throughput Internet of Things” was approved. The aimwas to study both the possibility of evolving current Global System forMobile communications (GSM) Enhanced Data Rates for GSM Evolution (EDGE)Radio Access Network (GERAN) system and the design of a new accesssystem towards low complexity and low throughput radio access technologyto address the requirements of cellular internet of things. Theobjectives of the study were: improved indoor coverage, support formassive number of low throughput devices, low delay sensitivity,ultra-low device cost, low device power consumption and (optimized)network architecture. As per the PCG #34 decisions, it was agreed tomove the normative phase of a single “clean-slate solution” to 3GPP LongTerm Evolution (LTE). This feature is called Narrowband Internet ofThings (NB-IOT).

3GPP LTE represents the project within the third generation partnershipproject, with an aim to improve the UMTS (Universal MobileTelecommunications Service) standard. 3GPP LTE radio interface offershigh peak data rates, low delays and increase in spectral efficiencies.LTE ecosystem supports both Frequency division duplex (FDD) and Timedivision duplex (TDD). This enables the operators to exploit both thepaired and unpaired spectrum since LTE has flexibility in bandwidth asit supports 6 bandwidths 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz and 20MHz.

The objective of this new work item on NB-IOT is to specify a radioaccess for cellular internet of things, based to a great extent on anon-backward-compatible variant of E-UTRA, that addresses improvedindoor coverage, support for massive number of low throughput devices,low delay sensitivity, ultra low device cost, low device powerconsumption and (optimized) network architecture.

NB-IoT should support 3 different modes of operation: (1) ‘Stand-aloneoperation’ utilizing for example the spectrum currently being used byGERAN systems as a replacement of one or more GSM carriers. In principleit operates on any carrier frequency which is neither within the carrierof another system not within the guard band of another system'soperating carrier. The other system can be another NB-IOT operation orany other RAT e.g. LTE. (2) ‘Guard band operation’ utilizing the unusedresource blocks within a LTE carrier's guard-band. The term guard bandmay also interchangeably be called guard bandwidth. (3) ‘1 n-bandoperation’ utilizing resource blocks within a normal LTE carrier. Thein-band operation may also interchangeably be called in-bandwidthoperation.

In NB-IoT, the downlink transmission is based on OFDM with 15 kHzsubcarrier spacing for all the scenarios: standalone, guard-band, andin-band. For UL transmission, both multi-tone transmissions based onSC-FDMA, and single tone transmission is supported. A multi-tonetransmission is based on SC-FDMA with 15 kHz UL subcarrier spacing. Forthe single tone transmissions, two numerologies can be configurable bythe network 3.75 kHz and 15 kHz. A cyclic prefix is inserted.

This means that the physical waveforms for NB-IoT in downlink and alsopartly in uplink is similar to legacy LTE.

In the downlink design, NB-IoT supports both master informationbroadcast and system information broadcast which are carried bydifferent physical channels. For in-band operation, it is possible forNB-IoT UE to decode the narrowband physical broadcast channel (NB-PBCH)without knowing the legacy physical resource block (PRB) index. NB-IoTsupports both downlink physical control channel (NB-PDCCH) and downlinkphysical shared channel (PDSCH). The operation mode of NB-IoT must beindicated to the UE, and currently 3GPP is considering indication bymeans of NB-SSS (secondary synchronization signal), NB-MIB (masterinformation block) or perhaps other downlink signals.

NB-IoT supports physical broadcast channel (NPBCH), physical downlinkcontrol channel (NPDCCH), physical downlink shared channel (PDSCH),physical uplink control channel (NPUCCH), physical uplink shared channel(NPUSCH), physical random access channel (NPRACH).

The general design principle of NB-IoT follows that of legacy LTE.Downlink synchronization signal consists of primary synchronizationsignal (NPSS) and secondary synchronization signal (NSSS). Theperiodicity of NPSS transmission is 10 ms.

Also cell specific reference symbols (NRS) are defined for NB-IoT. FIG.3 shows the NRS reference symbols for different operation modes; namely,for NB-IoT in-band and guardband/stand-alone scenarios.

Channel Arrangement in NB-IoT

The channel raster for all operation modes of NB-IoT is 100 kHz.However, the carrier frequency of an NB-IoT channel may be at an offsetcompared to the 100 kHz grid. For example, as shown in FIG. 4, in caseof guard-band operation in 10 MHz system bandwidth the first PRBsadjacent to the PRBs 0-49 within the LTE transmission bandwidth arecentered at 4597.5 kHz and −4597.5 kHz.

FIG. 5 shows a table with the center frequency offset for the adjacentPRB in the higher frequency guard band for different LTE systembandwidths. The offset is the same to the adjacent PRB in the lowerguard band. The 1.4 MHz system bandwidth has been excluded since guardband operation is not seen as feasible. It can be seen that the centerfrequency of the guard band PRB is at multiples of 2.5 kHz off the 100kHz frequency raster. It has been agreed in 3GPP that the DL and ULcenter frequency of the NB-IoT can be described as

F _(DL) =F _(DL_low)+0.1(N _(DL) −N _(Offs-DL))+0.0025*(2M _(DL)+1)  (1)

F _(UL) =F _(UL_low)+0.1(N _(UL) −N _(Offs-UL))+0.0025*(2M _(UL))  (2)

Where N_(DL) and N_(UL) are E-UTRA Absolute Radio Frequency ChannelNumber (EARFCN). M_(DL) and M_(UL) are the offset of NB-IoT channel tothe raster and

M _(DL)∈{−10,−9,−8,−7,−6,−5,−4,−3,−2,−1,−0.5,0,1,2,3,4,5,6,7,8,9},

M _(UL)∈{−10,−9,−8,−7,−6,−5,−4,−3,−2,−1,0,1,2,3,4,5,6,7,8,9}.

It has also been agreed that the UL frequency carrier is to bedetermined as follows for all deployment scenarios. For initial access,the NB-IoT DL/UL frequency separation is configured by higher layers(SIBx) and is cell-specific. After the initial random access proceduresuccess, there can also be a UE specific configuration for the NB-IoTDL/UL frequency separation.

This means that based on the network signaling, the spacing between theTX and RX may be fixed or may be variable.

NB-IoT Out of Band Emission

The spectrum emission mask of NB-IoT UE applies to frequencies(Δf_(OOB)) starting from the ± edge of the assigned NB-IoT UE channelbandwidth. The power of any category NB1 UE emission shall not exceedthe levels specified in the table shown in FIG. 6.

The Background section of this document is provided to place embodimentsof the present disclosure in technological and operational context, toassist those of skill in the art in understanding their scope andutility. Unless explicitly identified as such, no statement herein isadmitted to be prior art merely by its inclusion in the Backgroundsection.

SUMMARY

One or more embodiments herein include a method for configuring a radionode to transmit, within a guard band of a first radio access technology(RAT), a radio signal according to a second RAT. The method comprisesdetermining, based on a channel bandwidth of the first RAT, one or moretransmit parameters for transmission of the radio signal according tothe second RAT within the guard band of the first RAT, for transmissionof the radio signal to comply with emission limits for the first RAT.The one or more transmit parameters include a frequency position of theradio signal within the guard band for the first RAT. The method alsocomprises configuring the radio node with the one or more transmitparameters for transmitting the radio signal according to the second RATwithin the guard band of the first RAT.

In some embodiments, the one or more transmit parameters include acarrier frequency on which the radio signal is to be transmittedaccording to the second RAT. In this case, determining the one or moretransmit parameters may comprise determining the carrier frequency basedon an edge frequency defining an edge of the channel bandwidth of thefirst RAT and a defined frequency offset with respect to that edgefrequency. In some embodiments, the method may further comprisedetermining the defined frequency offset based on the channel bandwidthof the first RAT, with defined frequency offsets defined for differentpossible channel bandwidths of the first RAT. Alternatively oradditionally, the defined frequency offset may be specified based onemission requirements for the first RAT.

In some embodiments, determining the one or more transmit parameters maycomprise determining the frequency position of the radio signal suchthat a spectral emission mask governing transmission of the radio signalaccording to the second RAT is within a spectral emission mask governingthe first RAT.

In some embodiments, the emission limits for the second RAT arespecified as nominal emission limits applicable for transmitting a radiosignal according to the second RAT irrespective of whether the radiosignal is transmitted in the guard band for the first RAT and additionalemission limits applicable in addition to the nominal emission limitsfor transmitting a radio signal according to the second RAT in the guardband for the first RAT. In this case, the additional emission limits maydepend on a frequency offset of the radio signal from an edge of achannel bandwidth for the first RAT, and the additional emission limitsmay be enforced when the frequency offset is smaller than a definedthreshold and are not enforced when the frequency offset is greater thanthe defined threshold. In some of these embodiments, the definedthreshold depends on a size of the channel bandwidth for the first RAT.

In some embodiments, a spectrum emission mask for the second RAT appliesto frequencies starting from an edge of a channel bandwidth of thesecond RAT. In this case, determining the one or more transmitparameters may comprise determining the frequency position based onrequirements specified for the spectrum emission mask for the second RATregarding an offset frequency from an edge of the channel bandwidth ofthe first RAT. In some of these embodiments, the offset frequencydepends on a size of the channel bandwidth of the first RAT.Alternatively, determining the one or more transmit parameters maycomprise determining the frequency position based on a table thatspecifies respective offset frequencies required for different possiblesizes of the channel bandwidth of the first RAT.

In some embodiments, determining the one or more transmit parameters maycomprise determining the frequency position based on a requirement of atleast a certain frequency offset between an edge of the channelbandwidth of the first RAT and an edge of a channel bandwidth of thesecond RAT. In some of these embodiments, the certain frequency offsetrequired depends on a size of the channel bandwidth of the first RAT.

In some embodiments, determining the one or more transmit parameters maycomprise determining the frequency position based on a requirementregarding an offset frequency from an edge of the channel bandwidth ofthe first RAT.

In some embodiments, determining the one or more transmit parameters maycomprise determining the one or more transmit parameters fortransmission of the radio signal to comply with emission limits for boththe first and second RATs.

In some embodiments, the method is performed by a base station, andwherein said configuring comprises indicating the one or more transmitparameters to the radio node. Alternatively, the method may be performedby the radio node and may further comprise transmitting the radio signalas configured with the one or more transmit parameters.

In any of these embodiments, the radio node may be a user equipment.

Embodiments also include corresponding apparatus, computer programs,carriers, and non-transitory computer readable mediums.

For example, some embodiments include a base station for configuring aradio node to transmit, within a guard band for a first radio accesstechnology (RAT), a radio signal according to a second RAT. The basestation may be configured to determine, based on a channel bandwidth ofthe first RAT, one or more transmit parameters for transmission of theradio signal according to the second RAT, for transmission of the radiosignal to comply with emission limits for the first RAT. In someembodiments, the one or more transmit parameters include a frequencyposition of the radio signal within the guard band of the first RAT. Thebase station may also be configured to configure the radio node with theone or more transmit parameters for transmitting the radio signalaccording to the second RAT within the guard band of the first RAT. Thebase station may for example do so by indicating the one or moretransmit parameters to the radio node.

Embodiments also include a user equipment for transmitting, within aguard band for a first radio access technology (RAT), a radio signalaccording to a second RAT. The user equipment is configured todetermine, based on a channel bandwidth of the first RAT, one or moretransmit parameters for transmission of the radio signal according tothe second RAT, for transmission of the radio signal to comply withemission limits for the first RAT. The one or more transmit parametersmay include a frequency position of the radio signal within the guardband of the first RAT. The user equipment is also configured to transmitthe radio signal with the one or more transmit parameters according tothe second RAT within the guard band of the first RAT.

This section presents a simplified summary of the disclosure in order toprovide a basic understanding to those of skill in the art. This summaryis not an extensive overview of the disclosure and is not intended toidentify key/critical elements of embodiments of the disclosure or todelineate the scope of the disclosure. The sole purpose of this summaryis to present some concepts disclosed herein in a simplified form as aprelude to the more detailed description that is presented later.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will now be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of thedisclosure are shown. However, this disclosure should not be construedas limited to the embodiments set forth herein.

Rather, these embodiments are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the disclosureto those skilled in the art. Like numbers refer to like elementsthroughout.

FIG. 1A is a block diagram illustrating a subcarrier arrangement in anE-UTRA system.

FIG. 1B-1C is a table of E-UTRA channel numbers.

FIG. 2 is a block diagram illustrating an E-UTRA spectrum emission mask.

FIG. 3 is a block diagram illustrating cell-specific reference signalsfor NB-IoT for an in-band scenario and a guard band/standalone scenario.

FIG. 4 is a block diagram illustrating adjacent LTE PRB for guard bandoperation in 10 MHz LTE system bandwidth.

FIG. 5 is a block diagram illustrating center frequency offset of theguard band PRB for different LTE system bandwidths.

FIG. 6 is a block diagram illustrating NB-IoT UE spectrum emission mask.

FIG. 7 is a block diagram illustrating one embodiment of a system forconfiguring transmission in a guard band of a radio access technology inaccordance with various aspects as described herein.

FIG. 8 is a logic flow diagram of a method performed by a configuringnode according to some embodiments.

FIG. 9A is a graph illustrating overlap between the spectral emissionmasks of NB-IoT and LTE according to some embodiments.

FIG. 9B is a table illustrating respective offset frequencies fordifferent sizes of an LTE channel bandwidth according to someembodiments.

FIG. 10 is a block diagram of spectral emission masks for first andsecond RATs according to some embodiments.

FIG. 11 is a block diagram of spectral emission masks for first andsecond RATs according to other embodiments.

FIG. 12 is a block diagram of different RATs in the guardband of RAT1according to some embodiments.

FIG. 13 is a logic flow diagram of a method performed by a configuringnode according to other embodiments.

FIG. 14 is a logic flow diagram of a method performed by a configuringnode according to yet other embodiments.

FIG. 15 is a block diagram of a configuring node according to someembodiments.

FIG. 16 is a block diagram of a configuring node according to otherembodiments.

FIG. 17 is a block diagram of RAT2 power reduction in the guardband ofRAT1 according to some embodiments.

FIG. 18 illustrates one embodiment of a configuring node for configuringtransmission in a guard band of a radio access technology in accordancewith various aspects as described herein.

FIG. 19 illustrates another embodiment of a configuring node forconfiguring transmission in a guard band of a radio access technology inaccordance with various aspects as described herein.

FIG. 20 illustrates another embodiment of a configuring node forconfiguring transmission in a guard band of a radio access technology inaccordance with various aspects as described herein.

FIG. 21 illustrates another embodiment of a configuring node forconfiguring transmission in a guard band of a radio access technology inaccordance with various aspects as described herein.

of a configuring node in accordance with various aspects as describedherein.

DETAILED DESCRIPTION

FIG. 7 illustrates one embodiment of a system 700 for configuringtransmission in a guard band of a radio access technology in accordancewith various aspects as described herein. A first wireless communicationsystem (e.g., wideband LTE) may have a channel bandwidth 731 thatincludes a transmission bandwidth 733 and one or more guard bands 735a-b. In one example, the first wireless communication system may be oneor more wideband communication systems such as LTE, LTE-NX, UMTS, GSM,or the like. The first system may operate on frequency resources in thetransmission bandwidth 733 using a first radio access technology (RAT)(e.g., LTE, LTE-NX, UMTS, GSM, or the like), as referenced by 721. Inone example, a frequency resource may be a range of contiguousfrequencies, a physical resource block (PRB), or the like. In anotherexample, a frequency resource may be a single subcarrier, multiplecontiguous subcarriers, or the like. A second wireless communicationsystem (e.g., a Narrowband IoT system) may operate on one or morefrequency resources in the channel bandwidth 731 of the first system,outside such bandwidth, or both, using a second RAT (e.g., NB-IoT). Inone example, the second wireless communication system may be one morenarrowband communication systems such as NB-IoT.

In one embodiment, the first system may include a first network node 701(e.g., a base station) with a coverage area 703. The first network node701 may be configured to support frequency resources in the transmissionbandwidth 733 using the first RAT. Further, the first network node 701may serve a wireless device (e.g., user equipment, UE) 705 on thefrequency resources in the transmission bandwidth 733 using the firstRAT. The second system may include a second network node 711 (e.g., basestation) with a coverage area 713. The second network node 711 may beconfigured to support one or more frequency resources in the channelbandwidth 731 of the first system, outside such bandwidth, or both,using the second RAT. In one example, the second network node 711 may beconfigured to support frequency resources in the guard band 735 a of thefirst system using the second RAT, e.g., where the guard band is therange of frequencies between the edges of the transmission bandwidth andthe channel bandwidth. The second network node 711 may also serve thewireless device (e.g., UE) 705 on the one or more frequency resourcesusing the second RAT. For example, the second network node 711 may servethe wireless device 705 on one or more frequency resources in the guardband 735 a of the first system using the second RAT, as referenced by723. Each of the first and second network nodes 701 and 711,respectively, may be a base station, an access point, a wireless router,or the like. Further, the first network node 701 and the second networknode 711 may be the same network node or different network nodes.

In another embodiment, the second network node 711 may configure thewireless device 705 to transmit a radio signal 709, within the guardband 735 a for the first RAT, according to the second RAT. Further, thesecond network node 711 may determine one or more transmit parametersfor transmission of the radio signal 709 according to the second RAT, tocomply with emission limits for the first RAT. The one or more transmitparameters may include a frequency position of the radio signal 709within the guard band of the first RAT. Alternatively or additionally,the one or more transmit parameters may include a signal level of aradio signal, a maximum signal level of a radio signal, a frequencyallocation of subcarriers for the second system, a transport format(e.g., a modulation scheme, a coding scheme, a transport block size, orthe like), the like, or any combination thereof. Also, the secondnetwork node 711 may configure the wireless device 705 with the one ormore transmit parameters for transmitting the radio signal 709 withinthe guard band 735 a of the first RAT. The second network node 711 mayfor instance indicate the one or more transmit parameters to thewireless device 705, e.g., via system information, control signaling,etc.

In another embodiment, the wireless device 705 may configure itself totransmit the radio signal 709, within the guard band 735 a for the firstRAT, according to the second RAT. In particular, the wireless device 705may determine one or more transmit parameters for transmission of theradio signal 709 according to the second RAT, to comply with emissionlimits for the first RAT. Also, the wireless device 705 may configureitself with the one or more transmit parameters for transmitting theradio signal 709 within the guard band 735 a of the first RAT.

Although illustrated above in terms of configuring a wireless device 705to transmit a radio signal 709, embodiments herein also includeconfiguring any other sort of radio node (e.g., a base station) totransmit a radio signal. In general, therefore, embodiments hereininclude a so-called configuring node that configures a radio node totransmit a radio signal according to the second RAT within a guard bandof the first RAT, as described above. The configuring node may be theradio node itself, a radio node to which the radio signal is to betransmitted, or some other node.

Accordingly, FIG. 8 generally shows a method performed by any so-calledconfiguring node for configuring a radio node to transmit a radio signalaccording to the second RAT within a guard band of the first RAT. Asshown, the method includes determining one or more transmit parametersfor transmission of a radio signal according to the second RAT, tocomply with emission limits for the first RAT; that is, for thetransmission of the radio signal to comply with emission limits for thefirst RAT (Block 801). In some embodiments, the radio node alsodetermines the one or more transmit parameters for the transmission tocomply with emission limits for the second RAT, i.e., so that thetransmission complies with emission limits for both the first and secondRATs. Regardless, the method also includes configuring the radio nodewith the one or more transmit parameters for transmitting the radiosignal according to the second RAT within the guard band of the firstRAT (Block 803). Where the configuring node is a base station, forexample, such configuring may involve indicating the one or moretransmit parameters to the radio node, whereas where the configuringnode is the radio node itself, such configuring may involve controllingone or more settings or parameters of the radio node that governtransmission of the radio signal.

According to some embodiments, the one or more transmit parametersinclude a frequency position of the radio signal within the guard bandof the first RAT. The frequency position may be represented by orgoverned by a carrier frequency (e.g., center frequency) on which theradio signal is to be transmitted according to the second RAT. Thiscarrier frequency may in turn be represented by a channel number.Regardless of how the frequency position is represented or governed,some embodiments determine that frequency position based on certainrestrictions that are specified on the frequency position. Theserestrictions may ensure or guarantee that transmission of the radiosignal meets emission limits for the first RAT, e.g., that transmissionof the radio signal according to the second RAT does not cause moreemissions than those allowed for the first RAT.

In these and other embodiments, determining the one or more transmitparameters (e.g., frequency position) may be based on a channelbandwidth of the first RAT. Some embodiments, for example, determine thefrequency position based on a requirement regarding an offset frequencyfrom an edge of the channel bandwidth of the first RAT. In one suchembodiment, the frequency position is determined based on a requirementof at least a certain frequency offset between an edge of the channelbandwidth of the first RAT and an edge of a channel bandwidth of thesecond RAT. Where the frequency position is represented by the carrierfrequency, for instance, embodiments may determine the carrier frequencybased on an edge frequency defining an edge of the channel bandwidth ofthe first RAT and a defined frequency offset with respect to that edgefrequency.

Regardless of how the frequency position is represented, the certainfrequency offset required may depend on a size of the channel bandwidthof the first RAT, e.g., with larger offsets required for larger firstRAT channel bandwidth sizes. For example, respective frequency offsetsmay be defined for different possible channel bandwidths of the firstRAT. In particular, the frequency position may be determined based on atable that specifies respective offset frequencies required fordifferent possible sizes of the channel bandwidth of the first RAT.

No matter how defined or determined, though, the frequency offset insome embodiments guarantees that transmission of the radio signal meetsemission limits for the first RAT, e.g., at least assuming thattransmission of the radio signal meets emission limits for the secondRAT. Indeed, in some embodiments, the frequency offset is defined suchthat as long as transmission of the radio signal meets emission limitsfor the second RAT, transmission of the radio signal will be guaranteedto also meet emission limits for the first RAT, e.g., due to thefrequency offset to the channel bandwidth edge of the first RAT. In thissense, then, the frequency offset may be specified based on emissionrequirements for the first RAT. Accordingly, some embodimentseffectively determine the frequency position of the radio signal suchthat the spectral emission mask governing transmission of the radiosignal according to the second RAT is or remains within the spectralemission mask governing the first RAT. This may enhance the second RAT'sperformance in the guard band of the first RAT and/or reduce/avoidinterference to other systems operating in carrier frequencies adjacentto the carrier frequency of the first RAT.

Note therefore that the above embodiments may be specified in terms ofthe relation between spectral emission masks or spectral emissionrequirements, since those requirements are effectively defined withrespect to the channel bandwidth edge. For example, in some embodiments,a spectrum emission mask for the second RAT applies to frequenciesstarting from an edge of the channel bandwidth of the second RAT, andthe frequency position is determined based on requirements specified forthe spectrum emission mask for the second RAT regarding an offsetfrequency from an edge of the channel bandwidth of the first RAT.Because the spectrum emission mask defines the channel bandwidth edgefor the second RAT, this effectively means that there is a certainfrequency offset between the edge of the channel bandwidth of the secondRAT and the edge of the channel bandwidth of the first RAT. Again, thisfrequency offset may depend on a size of the channel bandwidth of thefirst RAT.

From another perspective, some embodiments may be specified in terms ofemission limits for the first RAT applying for certain frequencies. Theemission limits for the first RAT may for instance apply for anyfrequency that has (no more than) a certain offset between thatfrequency and an edge of the channel bandwidth of the second RAT.Because the frequencies to which the emission limits for the first RATapply start at the edge of the channel bandwidth of the first RAT, thiseffectively requires that there is a certain offset between the edge ofthe channel bandwidth of the first RAT and the edge of the channelbandwidth of the second RAT.

In some of these embodiments, for example, nominal emission limits areapplicable for transmitting a radio signal according to the second RATirrespective of whether the radio signal is transmitted in the guardband for the first RAT. Moreover, additional emission limits areapplicable in addition to the nominal emission limits for transmitting aradio signal according to the second RAT in the guard band for the firstRAT, depending on a frequency offset of the radio signal from the edgeof the channel bandwidth for the first RAT. The additional emissionlimits may be enforced when the frequency offset is smaller than adefined threshold and may not be enforced when the frequency offset isgreater than the defined threshold. This defined threshold may depend ona size of the channel bandwidth for the first RAT.

In fact, in some embodiments, a radio node herein transmits a radiosignal according to the second RAT in compliance with nominal emissionlimits specified for the second RAT. The radio node transmits the radiosignal selectively in compliance with additional emission limits whentransmitting the radio signal in a guard band of the first RAT. That is,the radio node transmits the radio signal without regard to theadditional emission limits when transmitted outside of the guard band ofthe first RAT, but transmits the radio signal in compliance with thoseadditional emission limits when transmitted in the guard band. Theadditional emission limits may therefore be referred to as guard bandspecific emission limits. In some embodiments, the additional emissionlimits specify emission limits based on a channel bandwidth of the firstRAT and/or a frequency offset of the radio signal from an edge of thefirst RAT's channel bandwidth, e.g., so as to limit emissionsdifferently depending on the channel bandwidth and frequency offset. Theemission limits here may limit out of band emissions, in band emissions,and/or adjacent channel leakage (e.g., in terms of ACLR, etc.).

Consider the following examples of the above embodiments, wherereference to RAT1 concerns the first RAT above and reference to RAT2concerns the second RAT above. The signal in RAT1 should meet certainemission requirements for outside of the channel bandwidth. However a UEor a network node that is in RAT2 heretofore meets the emissionrequirements of RAT2 alone. When RAT2 operates in the guard-band ofRAT1, the network node and/or the UE in RAT2 needs to meet bothrequirements.

FIG. 9A shows as an example a NB-IoT emission mask that is placed in theguard band of a 10 MHz LTE, where LTE and NB-IoT in this case are thefirst and second RATs respectively. The emission mark of NB-IoT isrepresented by a solid line and the emission mask of the 10 MHz LTE isrepresented by dotted lines. As it is shown in the small box in FIG. 9A,the emission mask of the NB-IoT crosses over the emission mask of LTE.

In order to guarantee that the signal level of the radio node (e.g., UEor base station BS) in RAT2, including its in-band and out-of-bandemission requirements, meets the requirements of RAT1, some embodimentsherein specify certain restrictions on the operating carrier of the RAT2or the emission requirements of RAT2 in the guard-band. The embodimentsmay for instance determine an absolute frequency or channel number,indicate it, and adapt the RAT2 carrier frequency to it. The steps ofthese embodiments can be done at a network node or a UE node or in acollaboration between the two nodes. Regardless, the embodiments ensurethat the radio node (e.g. UE or BS) operating in RAT2 within the guardband of RAT1 does not cause emissions more than the emissions caused byanother node (e.g. UE or BS) operating in RAT1. According to thisaspect, when a RAT2 operates inside the channel bandwidth of a RAT1, thecarrier frequency or channel number of a RAT2 is determined such thatthe spectrum emission mask of RAT2 and/or the signal level in RAT2remains within the limit of the spectrum mask of RAT1.

With respect to the NB-IoT and LTE example, in order to guarantee thatthe NB-IoT in the guard-band of LTE also meets LTE emissionrequirements, some embodiments require that NB-IoT in the guardband ofLTE has a certain offset from the LTE band-edge. Specifically, whenoperating in the guardband, in addition to the spectrum emissionrequirements in FIG. 6, a category NB1 UE should meet the additionalrequirements in the table shown in FIG. 9B, regarding the offsetfrequency from the edge of the LTE channel bandwidth. This tablespecifies additional requirements for category NB1 UE spectrum emissionmask.

Another exemplary rule in these embodiments is illustrated in FIG. 10.As shown, the channel bandwidth 1002 of the first RAT has an upperchannel edge frequency f2_u defining the upper edge of the channelbandwidth 1002. Within the channel bandwidth 1002, the guard band isdefined between the upper channel edge frequency f1_u and the uppertransmission edge frequency f2_u defining the edge of the channelbandwidth 1002. FIG. 10 also shows the channel bandwidth 904 of thesecond RAT as having an upper channel edge frequency f4 defining an edgeof the channel bandwidth 1004, with a guard band defined between thatupper channel edge frequency f4 and an upper transmission edge frequencyf3. The carrier (i.e., center) frequency of the second RAT is shown asfc2_u. Notably, FIG. 10 shows that in some embodiments the carrierfrequency in the second RAT is determined such that f4<f2_u; that is,such that the edge of the channel bandwidth of the second RAT is offsetfrom the edge of the channel bandwidth of the first RAT. This requiresthat the center frequency of RAT2 is less than the upper channel edgefrequency f2_u. The center frequency of operation is typically denotedby a frequency channel number such as EARFCN.

The exemplary frequencies f2_u and f4 in the above constraint in someembodiments are different breaking points in a spectrum emission mask,in which case the most stringent one applies. This is shown in FIG. 11,where the most stringent requirement in this example is f6<f5_u.

Note that the constraint in the above examples (e.g., on the frequencyposition of the radio signal of the second RAT) can be represented as arule relative to any of a number of possible frequency locationreferences. In one example, the rule constrains the central frequency ofRAT2 with respect to the channel bandwidth of RAT1, the transmissionbandwidth configuration of RAT1, etc.

According to one example of such rule, a frequency (fc2) for RAT2operation of a node in a guard band of RAT1 can be expressed by thefollowing general expression:

fc2=g1(f1,Δf)  (3)

where f1 is the frequency of the edge of transmission BW of RAT1 and Δfis the offset from the edge of the transmission bandwidth (f1).

The value of Δf is chosen in some embodiments such that the emissionmask of the node (e.g. UE or BS) operating in RAT2 with center frequencyfc2 does not exceed the limits of emission mask of node (e.g. UE or BS)operating in RAT1. The emission mask is defined as power level atdifferent frequencies outside the transmission bandwidth of the node.The emission mask of RAT2 is considered to be within the limit of theemission mask of RAT1 provided that the power level of RAT2 emissionmask at any given frequency (fg) is not larger than the power level ofRAT1 emission mask at the same frequency (i.e., fg). The value of Δfdepends on the channel bandwidths of RAT1 and RAT2. Assuming RAT2 has afixed channel BW of 200 KHz (i.e. if RAT2 is NB-IoT), the values ofwould be defined for different channel BWs of RAT1 (e.g. 1.4, 3, 5, 10,15 and 20 MHz for LTE).

Typically fc2 is the center frequency of the RAT2 operation. It can beexpressed in terms of channel number e.g. EARFCN.

The RAT2 can be operated in the guard band occurring above thetransmission BW (f1_u) of RAT1 or in the guard band below thetransmission BW (f1_l) of RAT1. Assume that fc2_u and fc2_l denote thefrequencies of the RAT2 operation in the guard band above f1_u and inthe guard band below f1_l respectively. The expression (3) can beextended for the two operations in upper and lower guard bands asfollows:

fc2_u=g2(f1_u,Δf)  (4)

fc2_l=g3(f1_l,Δf)  (5)

The uplink and downlink center frequencies for RAT2 operations in upperguard band of RAT1 are expressed by fc2_u_ul and fc2_u_dl and aredetermined by using the following expressions:

fc2_u_ul=g4(f1_u_ul,Δf1)  (6)

fc2_u_dl=g5(f1_u_dl,Δf2)  (7)

where Δf1 and Δf2 are the frequency offsets for UL and DL respectively.They can be the same (i.e. Δf1=Δf2=Δf) or can be different.

The uplink and downlink center frequencies for RAT2 operations in lowerguard band of RAT1 are expressed by fc2_l_ul and fc2_l_dl and aredetermined by using the following expressions:

fc2_l_ul=g6(f1_l_ul,Δf1)  (8)

fc2_l_dl=g7(f1_l_dl,Δf2)  (9)

As a particular example the rule defining fc2 for RAT2 operation in theupper guard band of RAT1 can be expressed by the following expression:

fc2_u<f1_u+Δf  (10)

As an example the rule defining fc2 for RAT2 operation in the lowerguard band of RAT1 can be expressed by the following expression:

fc2_l>f1_l−Δf  (11)

As a particular example the uplink and downlink center frequencies forRAT2 operations in upper guard band of RAT1 (fc2_u_ul and fc2_u_dl) aredetermined by using the following expressions:

fc2_u_ul<f1_u_ul+Δf1  (12)

fc2_u_dl<f1_u_dl+Δf2  (13)

Also as a particular example the uplink and downlink center frequenciesfor RAT2 operations in lower guard band of RAT1 (f2 c_l_ul and fc2_l_dl)are determined by using the following expressions:

fc2_l_ul>f1_l_ul−Δf1  (14)

fc2_l_dl>f1_l_dl−Δf2  (15)

The above descriptions apply to both UE and the network node, so thereare restrictions on both downlink and uplink frequencies for RAT2. IfRAT2 has flexible TX-RX frequency separation, then the two restrictionsare independent from one another. The flexible TX-RX frequencyseparation is also called as variable TX-RX frequency separation orvariable TX-RX frequency spacing.

According other embodiments, the absolute channel number or offset tothe channel raster may be determined, indicated, and adapted. That is,in some embodiments, the rule for determining the position of RAT2 interms of frequency of operation inside the guard-band of RAT1 isspecified in the form of Absolute Radio Frequency Channel Number(EARFCN) and/or the offset to the channel raster.

Examples of such rules can be a certain constraint on N_(DL)/M_(DL)and/or on N_(UL)/M_(UL). When RAT2 has a fixed TX-RX frequency spacingthen the two restrictions on the UL and DL frequencies of RAT2 are notindependent from each other. In case of fixed TX-RX spacing the centerfrequencies of the UL carrier and DL carrier are separated by a fixedfrequency offset or separation regardless of the values of UL and DLcarrier frequencies. The fixed TX-RX spacing is also interchangeablycalled as fixed TX-RX carrier frequency separation, TX-RX frequencyseparation, fixed TX-RX duplex, fixed TX-RX duplex spacing etc.

According to one aspect for a RAT2 with fixed TX-RX frequencyseparation, the center frequency fc2 in the UL and/or in DL of RAT2operation is adjusted to ensure that the fixed TX-RX frequencyseparation is maintained.

In one example the uplink and downlink center frequencies for RAT2operations in upper guard band of RAT1 (f2 c_u_ul and fc2_u_dl) areadjusted to fc2_u_ul′ and fc2_ul_dl′ to achieve fixed TX-RX separationand are determined by using the following expressions:

fc2_u_ul′<f1_u_ul+Δf1′  (16)

fc2_u_dl′<f1_u_dl+Δf2′  (17)

where difference between fc2_u_ul′ and fc2_ul_dl′ is always a fixed(i.e. the same value) for all sets of UL and DL center frequencies.

In another example the uplink and downlink center frequencies for RAT2operations in lower guard band of RAT1 (f2 c_l_ul and fc2_l_dl) areadjusted to fc2_l_ul′ and fc2_l_dl′ to achieve fixed TX-RX separationand are determined by using the following expressions:

fc2_l_ul′<f1_l_ul+Δf1′  (18)

fc2_l_dl′<f1_l_dl+Δf2′  (19)

In yet another example only one of the uplink and downlink centerfrequencies for RAT2 operations in upper guard band of RAT1 (f2 c_u_uland fc2_u_dl) is adjusted (e.g. fc2_u_ul′) to achieve fixed TX-RXseparation and are determined by using the following expressions:

fc2_u_ul′<f1_u_ul+Δf1′  (20)

fc2_u_dl<f1_u_dl+Δf2  (21)

In yet another example only one of the uplink and downlink centerfrequencies for RAT2 operations in lower guard band of RAT1 (f2 c_l_uland fc2_l_dl) is adjusted (e.g. fc2_l_ul′) to achieve fixed TX-RXseparation and are determined by using the following expressions:

fc2_l_ul′<f1_l_ul+Δf1′  (22)

fc2_l_dl<f1_l_dl+Δf2  (23)

Yet other embodiments concern determining additional emissionrequirements for operation of RAT2 when operating inside the channelbandwidth of RAT 1. According to these embodiments, additional emissionrequirements are enforced when RAT2 is within the guard band of RAT1 andis within a certain distance from the RAT1 channel edge. To avoid RAT2emissions violating the spectrum mask of RAT1, additional emissionrequirement can be applied for RAT2 when it operates in the guard bandof RAT1.

In an exemplary embodiment, the additional emission requirement dependson the frequency of the operation or bandwidth of RAT2. The additionalemission mask in this case becomes tighter for certain frequenciescloser to the channel edge of RAT1 while it is more relaxed or does notexist when RAT2 has a larger margin to the edge of the RAT1 channel. Inthis case one or several threshold frequencies can be defined andcorresponding to each threshold there is a certain emission masks apply.

As an example, FIG. 12 shows a RAT2 that is operating in the guard bandof RAT1 at center frequency fc2 and a RAT3 that operates at fc3. In thiscase, besides the corresponding spectrum emission mask (SEM) for RAT2and RAT3, according to this method, additional spectrum emission masksapply to RAT2 and RAT3 which depend on their frequency of operation,

SEM2=g18(fc2)

SEM3=g19(fc3)

where g18( ) and g19( ) are different spectrum emission masks and SEM3is tighter than SEM2.

In view of the above, a NB-IoT network node or UE should meet theregulatory emission requirements as well as standard emissionrequirements as specified by 3GPP. However the signaling that determinesUL and DL carrier frequency according to equations (1) and (2), onlyspecifies the center carrier frequency for NB-IoT and does not guaranteethat the emission requirements are met. There are emission requirementsfor both NB-IoT UE and NB-IoT BS, but when operating in the guard-bandof LTE, they not only should meet the NB-IoT emission requirements, butalso they should meet emission requirement of the hosting LTE system.

One or more embodiments herein include methods to determine requirementsfor a RAT2 (e.g. NB-IoT) operating in the guard-band of RAT1 (e.g. LTE)such that node operating RAT2 meets the general requirement of the RAT1system. The method is implemented in a UE and a network node:

The method in a network node operating RAT2 within a guard band of RAT1,comprising the steps of: (i) determining an uplink carrier frequency(fc2_ul) for operating RAT2 within a guard band of RAT1, wherein fc2_ulis a function of at least a frequency (f1_ul) defining the edge oftransmission bandwidth of RAT1 (BW1) and a frequency offset parameter(Δf1) wrt f1_ul, wherein the function is chosen to ensure that RAT2operation at fc2_ul follows the radio emission requirement of RAT1; and(ii) configuring the UE with the information related to the determinedvalue of fc2_ul.

The method in a network node operating RAT2 within a guard band of RAT1,comprises the steps of: (i) determining a downlink carrier frequency(fc2_dl) for operating

RAT2 within a guard band of RAT1, wherein fc2_dl is a function of atleast a frequency (f1_dl) defining the edge of transmission bandwidth ofRAT1 (BW1) and a frequency offset parameter (Δf2) wrt f1_dl, wherein thefunction is chosen to ensure that RAT2 operation at fc2_dl follows theradio emission requirement of RAT1; and (ii) configuring the networknode with the determined value of fc2_dl.

Moreover, a method in a UE for operating RAT2 within a guard band ofRAT1 may comprise the steps of: (i) receiving information about anuplink carrier frequency (fc2_ul) for operating RAT2 within a guard bandof RAT1; (ii) deriving fc2_ul based on received information; (iii)determining whether the derived value of fc2_ul is a function of atleast a frequency (f1_ul) defining the edge of transmission bandwidth ofRAT1 (BW1) and a frequency offset parameter (Δf1) wrt f1_ul, wherein thefunction is chosen to ensure that RAT2 operation at fc2_ul follows theradio emission requirement of RAT1; and (iv) configuring the UE with thereceived value of fc2_ul provided that the RAT2 operation at fc2_ul willenable the UE to meet emission requirement of RAT1, otherwise notconfiguring the UE with the received value of fc2_ul.

One or more embodiments herein may guarantee that RAT2 BS and UEoperating inside the bandwidth of RAT1 do not violate emissionrequirements of RAT1. In some embodiments, the RAT2 performance isenhanced when it operates within the guard band of RAT1. In one or moreembodiments, the interference towards the systems operating in carrierfrequencies adjacent to the carrier frequency of RAT1 is reduced oravoided. Additionally or alternatively, the regulatory requirements interms of radio emissions are met by UE and BS when operating in theguard band of another RAT.

Embodiments herein also generally include the method shown in FIG. 13for configuring a radio node to transmit, within a guard band for afirst radio access technology (RAT), a radio signal according to asecond RAT. As shown, the method comprises determining one or moretransmit parameters for transmission of the radio signal according tothe second RAT, to comply with an emission limit governing transmissionof the radio signal at a particular frequency offset from an edge of achannel bandwidth of the first RAT (Block 1302). The method furthercomprises configuring the radio node with the one or more transmitparameters for transmitting the radio signal within the guard band ofthe first RAT (Block 1304).

Embodiments herein further include the method shown in FIG. 14 forconfiguring a radio node to transmit, within a guard band for a firstradio access technology (RAT), a radio signal according to a second RAT.The method comprises determining a carrier frequency on which the radiosignal is to be transmitted according to the second RAT, to be within adefined frequency offset from an edge of a transmission bandwidth of thefirst RAT (Block 1402). The method also comprises configuring the radionode with the carrier frequency for transmitting the radio signal withinthe guard band of the first RAT (Block 1404).

Note that a configuring node may perform any of the above processing.The configuring node may be the radio node itself, a radio node to whichthe radio signal is to be transmitted, or some other node. Regardless,the configuring node as described herein may perform any of theprocessing herein by implementing any functional means or units. In oneembodiment, for example, the configuring node comprises respectivecircuits or circuitry configured to perform the steps shown in FIGS. 8,13, and/or 14. The circuits or circuitry in this regard may comprisecircuits dedicated to performing certain functional processing and/orone or more microprocessors in conjunction with memory. In embodimentsthat employ memory, which may comprise one or several types of memorysuch as read-only memory (ROM), random-access memory, cache memory,flash memory devices, optical storage devices, etc., the memory storesprogram code that, when executed by the one or more processors, carriesout the techniques described herein.

FIG. 15 illustrates a configuring node 1502 in accordance with one ormore embodiments. As shown, the configuring node 1502 includesprocessing circuitry 1504 and communication circuitry 1506. Thecommunication circuitry 1506 is configured to transmit and/or receiveinformation to and/or from one or more other nodes, e.g., via anycommunication technology. In some embodiments, the configuring node 1502is a radio node, in which case such communication may occur via one ormore antennas that are either internal or external to the configuringnode 1502. The processing circuitry 1504 is configured to performprocessing described above, e.g., in FIGS. 8, 13, and/or 14, such as byexecuting instructions stored in memory. The processing circuitry 1502in this regard may implement certain functional means, units, ormodules.

FIG. 16 illustrates a configuring node 1602 implemented in accordancewith one or more other embodiments. As shown, the configuring node 1602implements various functional means, units, or modules, e.g., via theprocessing circuitry 1504 in FIG. 15 and/or via software code. Thesefunctional means, units, or modules, e.g., for implementing the methodin FIGS. 8, 13, and/or 14 include a determining module 1604 and aconfiguring module 1606 for implementing the determining and configuringsteps respectively in FIGS. 8, 13, and/or 14. In some embodiments, e.g.,such as where the configuring node 1602 is the radio node itself, atransmitting module 1608 may be included for transmitting the radiosignal.

Those skilled in the art will also appreciate that embodiments hereinfurther include corresponding computer programs.

A computer program comprises instructions which, when executed on atleast one processor of a node, cause the node to carry out any of therespective processing described above. A computer program in this regardmay comprise one or more code modules corresponding to the means orunits described above.

Embodiments further include a carrier containing such a computerprogram. This carrier may comprise one of an electronic signal, opticalsignal, radio signal, or computer readable storage medium.

In this regard, embodiments herein also include a computer programproduct stored on a non-transitory computer readable (storage orrecording) medium and comprising instructions that, when executed by aprocessor of a node, cause the node to perform as described above.

Embodiments further include a computer program product comprisingprogram code portions for performing the steps of any of the embodimentsherein when the computer program product is executed by a computingdevice. This computer program product may be stored on a computerreadable recording medium.

In view of the above, embodiments generally include a method forconfiguring a radio node to transmit, within a guard band for a firstradio access technology (RAT), a radio signal according to a second RAT.The method comprises determining one or more transmit parameters fortransmission of the radio signal according to the second RAT, to complywith emission limits for both the first and second RATs; and configuringthe radio node with the one or more transmit parameters for transmittingthe radio signal within the guard band of the first RAT.

In some embodiments, the one or more transmit parameters comprise afrequency position of the radio signal within the guard band for thefirst RAT.

Alternatively or additionally, the one or more transmit parameterscomprise a carrier frequency on which the radio signal is to betransmitted.

In some embodiments, said determining comprises determining a carrierfrequency on which the radio signal is to be transmitted according tothe second RAT, based on an edge frequency defining an edge of atransmission bandwidth of the first RAT and a defined frequency offsetwith respect to that edge frequency.

In some embodiments, said determining comprises determining a carrierfrequency on which the radio signal is to be transmitted according tothe second RAT, to be within a defined frequency offset from an edge ofa transmission bandwidth of the first RAT.

In some embodiments, the method further comprises determining thedefined frequency offset based on a channel bandwidth of the first RAT,with defined frequency offsets defined for different possible channelbandwidths of the first RAT.

In some embodiments, the defined frequency offset is specified based onemission requirements for the first RAT.

In some embodiments, the one or more transmit parameters comprise anAbsolute Radio Frequency Channel Number and/or an offset to a channelraster.

In some embodiments, wherein the one or more transmit parameterscomprise a signal level of the radio signal.

In some embodiments, said determining comprises determining the one ormore transmit parameters based on a transmission bandwidth of the firstRAT and/or a channel bandwidth of the first RAT.

In some embodiments, said determining comprises determining the one ormore transmit parameters such that a spectral emission mask governingtransmission of the radio signal according to the second RAT and/or asignal level of the radio signal is within a spectral emission maskgoverning the first RAT.

In some embodiments, the emission limits for the second RAT arespecified to ensure compliance with the emission limits for the firstRAT, and said determining comprises determining the one or more transmitparameters for transmission of the radio signal according to the secondRAT to comply with the emission limits for the second RAT.

In some embodiments, the emission limits for the second RAT arespecified as nominal emission limits applicable for transmitting a radiosignal according to the second RAT irrespective of whether the radiosignal is transmitted in the guard band for the first RAT and additionalemission limits applicable in addition to the nominal emission limitsfor transmitting a radio signal according to the second RAT in the guardband for the first RAT.

In some embodiments, the additional emission limits depend on afrequency or bandwidth of the radio signal.

In some embodiments, the additional emission limits depend on afrequency offset of the radio signal from an edge of a channel bandwidthfor the first RAT, with a tighter emission limits specified for asmaller frequency offset than a larger frequency offset.

Other embodiments herein include a method for configuring a radio nodeto transmit, within a guard band of a first radio access technology(RAT), a radio signal according to a second RAT. the method comprisesdetermining one or more transmit parameters for transmission of theradio signal according to the second RAT, to comply with an emissionlimit governing transmission of the radio signal at a particularfrequency offset from an edge of a channel bandwidth of the first RAT;and configuring the radio node with the one or more transmit parametersfor transmitting the radio signal within the guard band of the firstRAT.

In some embodiments, the emission limit is one of multiple differentemission limits governing transmissions at different possible frequencyoffsets from an edge of the channel bandwidth of the first RAT.

In some embodiments, the one or more transmit parameters comprise asignal level of the radio signal.

In some embodiments, said determining comprises determining the one ormore transmit parameters such that a spectral emission mask governingtransmission of the radio signal according to the second RAT and/or asignal level of the radio signal is within a spectral emission maskgoverning the first RAT.

In some embodiments, emission limits for the second RAT are specified toensure compliance with emission limits for the first RAT, and saiddetermining comprises determining the one or more transmit parametersfor transmission of the radio signal according to the second RAT tocomply with the emission limits for the second RAT.

In some embodiments, emission limits for the second RAT are specified asnominal emission limits applicable for transmitting a radio signalaccording to the second RAT irrespective of whether the radio signal istransmitted in the guard band for the first RAT and additional emissionlimits applicable in addition to the nominal emission limits fortransmitting a radio signal according to the second RAT in the guardband for the first RAT.

In some embodiments, the additional emission limits depend on afrequency or bandwidth of the radio signal.

In some embodiments, the additional emission limits depend on afrequency offset of the radio signal from an edge of a channel bandwidthfor the first RAT, with a tighter emission limits specified for asmaller frequency offset than a larger frequency offset.

Embodiments also include a method for configuring a radio node totransmit, within a guard band for transmission according to a firstradio access technology (RAT), a radio signal according to a second RAT.The method comprises determining a carrier frequency on which the radiosignal is to be transmitted according to the second RAT, to be within adefined frequency offset from an edge of a transmission bandwidth of thefirst RAT; and configuring the radio node with the carrier frequency fortransmitting the radio signal within the guard band of the first RAT.

In some embodiments, the method further comprises determining thedefined frequency offset based on a channel bandwidth of the first RAT,with defined frequency offsets defined for different possible channelbandwidths of the first RAT.

In some embodiments, the defined frequency offset is specified based onemission requirements for the first RAT.

In some embodiments, the method is implemented by the radio node, andfurther comprises transmitting the radio signal as configured with theone or more transmit parameters.

In some embodiments, the method is implemented by a base station,wherein the radio signal is to be transmitted to or from the basestation.

In some embodiments, the radio node is a user equipment.

Embodiments also include a configuring node for configuring a radio nodeto transmit, within a guard band for a first radio access technology(RAT), a radio signal according to a second RAT. The configuring node isconfigured to determine one or more transmit parameters for transmissionof the radio signal according to the second RAT, to comply with emissionlimits for both the first and second RATs; and configure the radio nodewith the one or more transmit parameters for transmitting the radiosignal within the guard band of the first RAT.

In some embodiments, the configuring node is configured to perform themethod of any of the above embodiments.

Embodiments further include a configuring node for configuring a radionode to transmit, within a guard band of a first radio access technology(RAT), a radio signal according to a second RAT. The configuring node isconfigured to: determine one or more transmit parameters fortransmission of the radio signal according to the second RAT, to complywith an emission limit governing transmission of the radio signal at aparticular frequency offset from an edge of a channel bandwidth of thefirst RAT; and configure the radio node with the one or more transmitparameters for transmitting the radio signal within the guard band ofthe first RAT.

In some embodiments, the configuring node is configured to perform themethod of any of the above embodiments.

Embodiments further include a configuring node for configuring a radionode to transmit, within a guard band for transmission according to afirst radio access technology (RAT), a radio signal according to asecond RAT. The configuring node is configured to: determine a carrierfrequency on which the radio signal is to be transmitted according tothe second RAT, to be within a defined frequency offset from an edge ofa transmission bandwidth of the first RAT; and configure the radio nodewith the carrier frequency for transmitting the radio signal within theguard band of the first RAT.

In some embodiments, the configuring node is configured to perform themethod of any of the above embodiments.

Embodiments further include a configuring node for configuring a radionode to transmit, within a guard band for a first radio accesstechnology (RAT), a radio signal according to a second RAT. Theconfiguring node comprises a determining module for determining one ormore transmit parameters for transmission of the radio signal accordingto the second RAT, to comply with emission limits for both the first andsecond RATs; and a configuring module for configuring the radio nodewith the one or more transmit parameters for transmitting the radiosignal within the guard band of the first RAT.

In some embodiments, the configuring node is configured to perform themethod of any of the above embodiments.

Embodiments further include a configuring node for configuring a radionode to transmit, within a guard band of a first radio access technology(RAT), a radio signal according to a second RAT. The configuring nodecomprises a determining module for determining one or more transmitparameters for transmission of the radio signal according to the secondRAT, to comply with an emission limit governing transmission of theradio signal at a particular frequency offset from an edge of a channelbandwidth of the first RAT; and a configuring module for configuring theradio node with the one or more transmit parameters for transmitting theradio signal within the guard band of the first RAT.

In some embodiments, the configuring node is configured to perform themethod of any of the above embodiments.

Embodiments further include a configuring node for configuring a radionode to transmit, within a guard band for transmission according to afirst radio access technology (RAT), a radio signal according to asecond RAT. The configuring node comprises a determining module fordetermining a carrier frequency on which the radio signal is to betransmitted according to the second RAT, to be within a definedfrequency offset from an edge of a transmission bandwidth of the firstRAT; and a configuring module for configuring the radio node with thecarrier frequency for transmitting the radio signal within the guardband of the first RAT.

In some embodiments, the configuring node is configured to perform themethod of any of the above embodiments.

Embodiments further include a configuring node for configuring a radionode to transmit, within a guard band for a first radio accesstechnology (RAT), a radio signal according to a second RAT. Theconfiguring node comprises a processor and a memory, the memorycontaining instructions executable by the processor whereby theconfiguring node is configured to: determine one or more transmitparameters for transmission of the radio signal according to the secondRAT, to comply with emission limits for both the first and second RATs;and configure the radio node with the one or more transmit parametersfor transmitting the radio signal within the guard band of the firstRAT.

The memory may contain instructions executable by the processor wherebythe configuring node is configured to perform the method of any of theabove embodiments.

Embodiments further include a configuring node for configuring a radionode to transmit, within a guard band of a first radio access technology(RAT), a radio signal according to a second RAT. The configuring nodecomprises a processor and a memory, the memory containing instructionsexecutable by the processor whereby the configuring node is configuredto: determine one or more transmit parameters for transmission of theradio signal according to the second RAT, to comply with an emissionlimit governing transmission of the radio signal at a particularfrequency offset from an edge of a channel bandwidth of the first RAT;and configure the radio node with the one or more transmit parametersfor transmitting the radio signal within the guard band of the firstRAT.

The memory may contain instructions executable by the processor wherebythe configuring node is configured to perform the method of any of theabove embodiments.

Embodiments also include a configuring node for configuring a radio nodeto transmit, within a guard band for transmission according to a firstradio access technology (RAT), a radio signal according to a second RAT.The configuring node comprises a processor and a memory, the memorycontaining instructions executable by the processor whereby theconfiguring node is configured to: determine a carrier frequency onwhich the radio signal is to be transmitted according to the second RAT,to be within a defined frequency offset from an edge of a transmissionbandwidth of the first RAT; and configure the radio node with thecarrier frequency for transmitting the radio signal within the guardband of the first RAT.

The memory may contain instructions executable by the processor wherebythe configuring node is configured to perform the method of any of theabove embodiments.

Embodiments also include a computer program, comprising instructionswhich, when executed on at least one processor of a configuring node,cause the at least one processor to carry out the method according toany of the above embodiments.

Embodiments further include a carrier containing the computer program.The carrier is one of an electronic signal, optical signal, radiosignal, or computer readable storage medium.

Embodiments herein also include methods to adapt transmission parametersof an NB-IoT node when operating in the guard band of an E-UTRA carrierto ensure that the NB-IoT node meets emission requirements of E-UTRA.The methods apply to both network node and the UE node. To enable theNB-IoT node to meet emission requirements of E-UTRA, the adaptation canbe done on one or more transmission parameters used by the NB-IoT nodefor transmitting signals. Examples of the transmission parameters arethe power of the NB-IoT signal, maximum power of NB-IoT signal,frequency allocation of the NB-IoT subcarriers, transport format (e.g.MCS that is used in the carriers, number of data or transport blocks ina data channel, size of data or transport block etc.), etc.

In a first embodiment, a method in a node comprises the steps of: (i)determining whether RAT2 operates in the guard band (GB) of RAT1,wherein the GB is the range of frequencies between the channel BW andthe transmission BW of RAT1; (ii) if RAT2 operates in the guard band ofRAT1 then adapting or restricts one or more parameters related totransmission of signals in RAT2 to ensure that RAT2 meets emissionrequirements of RAT1 or at least RAT2 emission does not exceed the limitof emissions of RAT1; and (iii) transmit signals in RAT2 based onadapted or restricted set of transmission parameters.

In a second embodiment, a method in node comprises the steps of: (i)determining whether RAT2 operates in the guard band of RAT2, wherein theGB is the range of frequencies between the channel BW and thetransmission BW of RAT1; (ii) determining an offset (Δf) of a centerfrequency (fc2) of RAT2 from the edge of the transmission bandwidth ofRAT1; (iii) If RAT2 operates in the guard band of RAT1 and magnitude ofΔf is below a threshold (H) then adapting or restricting one or moreparameters related to transmission of signals in RAT2; (iv) If RAT2operates in the guard band of RAT1 and magnitude of Δf is larger than Hthen not adapting or restricting one or more parameters related totransmission of signals in RAT2; (v) Transmit signals in RAT2 based onadapted or unadapted set of transmission parameters.

In a third embodiment a method in a node comprises the steps of: (i)Determining whether RAT2 operates in the guard band of RAT2, wherein theGB is the range of frequencies between the channel BW and thetransmission BW of RAT1; (ii) Determining an offset (Δf) of a centerfrequency (fc2) of RAT2 from the edge of the transmission bandwidth ofRAT1; (iii) If RAT2 operates in the guard band of RAT1 and magnitude ofΔf is below a threshold (H) then adapting or restricting one or moreparameters related to transmission of signals in RAT2 to a first set ofparameters to ensure that RAT2 meets emission requirements of RAT1 or atleast RAT2 emission does not exceed the limit of emissions of RAT1; (iv)If RAT2 operates in the guard band of RAT1 and magnitude of Δf is largerthan H then adapting or restricting one or more parameters related totransmission of signals in RAT2 to a second set of parameters to ensurethat RAT2 meets emission requirements of RAT1 or at least RAT2 emissiondoes not exceed the limit of emissions of RAT1, wherein the firstadapted set comprises of at least one more parameter more restrictedthan the corresponding parameter in the second adapt set; (vi) andTransmit signals in RAT2 based on the first or the second set of theadapted or restricted transmission parameters.

The methods outlined above provide that RAT2 BS and UE operating insidethe bandwidth of RAT1 do not violate emission requirements of RAT1. TheRAT2 performance is enhanced when it operates within the guard band ofRAT1. In some embodiments, the interference towards the systemsoperating in carrier frequencies adjacent to the carrier frequency ofRAT1 is reduced or avoided. In some embodiments, the regulatoryrequirements in terms of radio emissions are met by UE and BS whenoperating in the guard band of another RAT.

More particularly, a node performs certain steps or execute a procedurein order to ensure that when a node operates RAT2 in the guard band ofthe channel bandwidth of a RAT1, then the radio emission requirements ofRAT2 remains within the limit of the radio emission requirements ofRAT1.

An example of radio emission requirement is spectrum emission mask. Insuch a case, the values of one or more transmission parameters arechosen or adapted is such that the emission mask of the node (e.g. UE orBS) operating in RAT2 with center frequency fc2 in the guard band ofRAT1 does not exceed the limits of emission mask of node (e.g. UE or BS)operating in RAT1. The emission mask is defined as power level atdifferent frequencies outside the transmission BW of the node. Theemission mask of RAT2 is considered to be within the limit of theemission mask of RAT1 provided that the power level of RAT2 emissionmask at any given frequency (fg) is not larger than the power level ofRAT1 emission mask at the same frequency.

Examples of transmission parameters are transmit power, average transmitpower, maximum transmit power, transport format or data format of atransport channel, number of physical resources (e.g. resource blocks(RBs), subcarriers, resource elements etc.) etc. Parameters describingtransport channel are number of transport blocks per transport channel,transport block size per transport block, modulation and coding schemeetc.

The reduction or adaptation in UL transport channel characteristics willalso reduce UL RBs and UL transmit power on a carrier used by the nodefor transmitting signals of RAT2. This will in turn reduce emissionscaused by RAT2 and based on the reduced set of transmission parameters,RAT2 emission requirements will remain within RAT1 emissionrequirements.

In one exemplary implementation the node may adapt or limit one or moretransmission parameters of RAT2 provided that RAT2 is configured tooperate anywhere within the guard band of RAT1 i.e. adapt RATtransmission parameters if RAT2 center frequency (fc2) is anywherewithin the GB of RAT1. This rule can be pre-defined or it can beconfigured by another node or it can be autonomously selected by thenode itself (e.g. whenever RAT2 does not meet emission requirements ofRAT1).

In yet another exemplary implementation the node does not need to adaptor limit one or more transmission parameters of RAT2 provided that RAT2is configured to operate within certain range of frequencies within theguard band of RAT1 i.e. adapt RAT transmission parameters only if RAT2center frequency (fc2) is within certain ranges of carrier frequenciesthe GB of RAT1. This rule can also be pre-defined or it can beconfigured by another node or it can be autonomously selected by thenode itself (e.g. whenever RAT2 does not meet emission requirements ofRAT1). An example of certain ranges of frequencies are those frequencies(e.g. center frequency where RAT2 can operate) which are located atleast certain offset (Δf) from the edge of the transmission bandwidth ofRAT1. In other words of fc2 is far from the edge of RAT1 transmission BWthen the RAT2 does not need to limit the value of any transmissionparameters. The value of Δf depends on the channel bandwidths of RAT1and RAT2. Assuming RAT2 has a fixed channel BW of 200 KHz (i.e. if RAT2is NB-IoT), the values of would be defined for different channel BWs ofRAT1 (e.g. 1.4, 3, 5, 10, 15 and 20 MHz for LTE). The value of Δf ischosen such that the emission mask of the node (e.g. UE or BS) operatingin RAT2 with center frequency fc2 does not exceed the limits of emissionmask of node (e.g. UE or BS) operating in RAT1.

In a first method, the node performs the following main steps: (i)Determining whether RAT2 operates in the guard band of RAT2; (ii) IfRAT2 operates in the guard band of RAT1 then adapting or restricts oneor more parameters related to transmission of signals in RAT2; and (iii)Transmit signals in RAT2 based on adapted or restricted set oftransmission parameters.

In a second method the node performs the following main steps: (i)Determining whether RAT2 operates in the guard band of RAT2; (ii)Determining an offset (Δf) of a center frequency (fc2) of RAT2 from theedge of the transmission bandwidth of RAT1; (iii) If RAT2 operates inthe guard band of RAT1 and magnitude of Δf is below a threshold (H) thenadapting or restricting one or more parameters related to transmissionof signals in RAT2; (iv) If RAT2 operates in the guard band of RAT1 andmagnitude of Δf is larger than H then not adapting or restricting one ormore parameters related to transmission of signals in RAT2;

Transmit signals in RAT2 based on adapted or unadapted set oftransmission parameters.

In a third method the node performs the following main steps: (i)Determining whether RAT2 operates in the guard band of RAT2; (ii)Determining an offset (Δf) of a center frequency (fc2) of RAT2 from theedge of the transmission bandwidth of RAT1; (iii) If RAT2 operates inthe guard band of RAT1 and magnitude of Δf is below a threshold (H) thenadapting or restricting one or more parameters related to transmissionof signals in RAT2 to a first set of parameters; (iv) If RAT2 operatesin the guard band of RAT1 and magnitude of Δf is larger than H thenadapting or restricting one or more parameters related to transmissionof signals in RAT2 to a second set of parameters, wherein the firstadapted set comprises of at least one more parameter more restrictedthan the corresponding parameter in the second adapt set; and (v)Transmit signals in RAT2 based on the first or the second set of theadapted or restricted transmission parameters.

Examples of first and second sets of adapted parameters are maximumtransmit power of 17 dBm and 20 dBm respectively. Another example offirst and second set of adapted parameters are modulation of BPSK andQPSK respectively. Yet another example of first and second set ofadapted parameters are code rates of ⅓ and ½ respectively.

The adapted or limited or reduced set of transmission parameters may bepre-defined, configured by a network node or decided by the node itself.

In the following section various examples of adapting one or moretransmission parameters for transmitting signals on RAT2 within RAT1guard band are further elaborated with various examples.

According to this aspect of the disclosure, when a RAT2 operates insidethe channel bandwidth of a RAT1, the maximum transmission power of RAT2can be adapted such that the signal level of RAT2 remains within thelimit of the spectrum mask of RAT1. Examples of adapting thetransmission power of RAT2 can be a backoff in the transmission power ofthe network node, or applying maximum power reduction (MPR) oradditional maximum power reduction (A-MPR). The value of MPR isexpressed in dB. For example 2 dB reduction means reducing the maxtransmit power of the UE from 23 dBm to 21 dBm. The A-MPR defines the UEmaximum output power reduction (on top of the normal MPR) needed tofulfill certain emission requirements by accounting for factors such as:bandwidth, frequency band or resource block allocation. To enableapplication of A-MPR, the network signaling (NS) parameter value issignaled to the UE via system information in a UE specific channel or ina broadcast message. This allows the UE to acquire this information whenit camps on to a cell. The acquired NS value which is associated with acell is then used by the UE to map to certain A-MPR and reduce itsmaximum output power whenever it transmits in the uplink.

In one exemplary embodiment, the power level of RAT2 can be a functionof the frequency offset between the RAT2 and the edge of cannelbandwidth of RAT1. As an example if RAT2 has a large offset to the edgeof the RAT1 channel bandwidth, then the maximum allowed power can beused for RAT2, i.e. zero power reduction can be used. While if RAT2 isclose to the edge of the RAT1, a power reduction can be used thatdepends on the offset to the edge of the channel bandwidth of RAT1. FIG.17 shows as an example a RAT2 that operates inside the guard-band of aRAT1, where RAT is has a reduced power in order to meet the emissionrequirements of RAT1.

According to this aspect of the disclosure, when a RAT2 operates insidethe channel bandwidth of a RAT1, the allocation of subcarriers isadapted to the spectrum mask of RAT1 and/or the offset between RAT2 toRAT1 channel edge. The adaptation is done such that RAT2 data aretransmitted on the subcarriers that are further away from the channeledge of RAT1, while subcarriers in RAT2 that are closer to the edge ofthe channel bandwidth of RAT1 are left empty.

According to this aspect of the disclosure, when a RAT2 operates insidethe channel bandwidth of a RAT1, modulation and coding scheme (MCS) thatis used for RAT2 is adapted to the spectrum mask of RAT1 and/or theoffset between RAT2 to RAT1 channel edge. The adaptation is done suchthat MCS that if RAT2 is operating close to the edge of the channelbandwidth in RAT1, then MCS with less maximum power and/or less envelopevariation is used. Example of modulation schemes with low envelopevariation are pi/2 BPSK or pi/4QPSK, and examples of high envelopevariation modulation are 16-QAM, 64QAM, etc.

Note that terminology such as base station, NodeB or eNode B and UEshould be considering non-limiting and does in particular not imply acertain hierarchical relation between the two; in general “NodeB” couldbe considered as device 1 and “UE” device 2, and these two devicescommunicate with each other over some radio channel. A generic termnetwork node is used in some embodiments. The network node can be a basestation, access point, NodeB or eNode B etc. A generic term wirelessdevice is used in some embodiments. The wireless device can be any typeof UE such as D2D UE, MTC UE, M2M UE etc. The MTC or M2M UE may also beinterchangeably called as, narrow band or narrow BW UE, category 0 UE,category M UE, low cost and/or low complexity UE etc. Yet anothergeneric term, radio node, may be used in some embodiments. The radionode may be a network node or a wireless device.

The UE may operate under either normal coverage or enhanced coveragewith respect to its serving cell. The enhanced coverage is alsointerchangeably called as extended coverage. The UE may also operate ina plurality of coverage levels (i.e. move within different coveragelevels) e.g. normal coverage, enhanced coverage level 1, enhancedcoverage level 2, enhanced coverage level 3 and so on.

In some embodiments a term operating bandwidth (BW) is used. Over theoperating BW the network node transmits to and/or receives signal fromone or more UEs in a cell. The operating bandwidth is interchangeablycalled as channel bandwidth, system bandwidth, transmission bandwidth,cell bandwidth, cell transmission BW, carrier bandwidth etc. Theoperating BW may be expressed in different units. Examples of units areKHz, MHz, number of resource blocks, number of resource elements, numberof subcarriers, number of physical channels, number of frequencyresource units etc. The frequency channel or carrier frequency overwhich a RAT operates is enumerated or addressed by a channel number akaabsolute radio frequency channel number (ARFCN) e.g. E-UTRA ARFCN(EARFCN) in LTE etc.

Despite particular applicability to NB-IoT in some examples, it will beappreciated that the techniques may be applied to other wirelessnetworks, including eMTC as well as to successors of the E-UTRAN. Thus,references herein to signals using terminology from the 3GPP standardsfor LTE should be understood to apply more generally to signals havingsimilar characteristics and/or purposes, in other networks.

A radio node herein is any type of node (e.g., a base station orwireless communication device) capable of communicating with anothernode over radio signals. A radio network node is any type of radio nodewithin a wireless communication network, such as a base station. Awireless communication device is any type of radio node capable ofcommunicating with a radio network node over radio signals. A wirelesscommunication device may therefore refer to a machine-to-machine (M2M)device, a machine-type communications (MTC) device, a NB-IoT device,etc. The wireless device may also be a user equipment (UE), however itshould be noted that the UE does not necessarily have a “user” in thesense of an individual person owning and/or operating the device. Awireless device may also be referred to as a radio device, a radiocommunication device, a wireless terminal, or simply a terminal—unlessthe context indicates otherwise, the use of any of these terms isintended to include device-to-device UEs or devices, machine-typedevices or devices capable of machine-to-machine communication, sensorsequipped with a wireless device, wireless-enabled table computers,mobile terminals, smart phones, laptop-embedded equipped (LEE),laptop-mounted equipment (LME), USB dongles, wireless customer-premisesequipment (CPE), etc. In the discussion herein, the termsmachine-to-machine (M2M) device, machine-type communication (MTC)device, wireless sensor, and sensor may also be used. It should beunderstood that these devices may be UEs, but are generally configuredto transmit and/or receive data without direct human interaction.

In an IOT scenario, a wireless communication device as described hereinmay be, or may be comprised in, a machine or device that performsmonitoring or measurements, and transmits the results of such monitoringmeasurements to another device or a network. Particular examples of suchmachines are power meters, industrial machinery, or home or personalappliances, e.g. refrigerators, televisions, personal wearables such aswatches etc. In other scenarios, a wireless communication device asdescribed herein may be comprised in a vehicle and may performmonitoring and/or reporting of the vehicle's operational status or otherfunctions associated with the vehicle.

FIG. 18 illustrates one embodiment of a configuring node for configuringtransmission in a guard band of a radio access technology in accordancewith various aspects as described herein.

FIG. 19 illustrates another embodiment of a configuring node forconfiguring transmission in a guard band of a radio access technology inaccordance with various aspects as described herein.

FIG. 20 illustrates another embodiment of a configuring node forconfiguring transmission in a guard band of a radio access technology inaccordance with various aspects as described herein.

Of course, despite particular applicability to NB-IoT in some examples,it will be appreciated that the techniques may be applied to otherwireless networks, including eMTC as well as to successors of theE-UTRAN. Thus, references herein to signals using terminology from the3GPP standards for LTE should be understood to apply more generally tosignals having similar characteristics and/or purposes, in othernetworks.

FIG. 12 illustrates another embodiment of a configuring node 1200 inaccordance with various aspects as described herein. In some instances,the configuring node 1200 may be referred as wireless device, a radionode, a network node, a base station (BS), an access point (AP), a userequipment (UE), a mobile station (MS), a terminal, a cellular phone, acellular handset, a personal digital assistant (PDA), a smartphone, awireless phone, an organizer, a handheld computer, a desktop computer, alaptop computer, a tablet computer, a set-top box, a television, anappliance, a game device, a medical device, a display device, a meteringdevice, or some other like terminology. In other instances, theconfiguring node 1200 may be a set of hardware components. In FIG. 12,the configuring node 1200 may be configured to include a processor 1201that is operatively coupled to an input/output interface 1205, a radiofrequency (RF) interface 1209, a network connection interface 1211, amemory 1215 including a random access memory (RAM) 1217, a read onlymemory (ROM) 1219, a storage medium 1221 or the like, a communicationsubsystem 1251, a power source 1233, another component, or anycombination thereof. The storage medium 1221 may include an operatingsystem 1223, an application program 1225, data 1227, or the like.Specific devices may utilize all of the components shown in FIG. 12, oronly a subset of the components, and levels of integration may vary fromdevice to device. Further, specific devices may contain multipleinstances of a component, such as multiple processors, memories,transceivers, transmitters, receivers, etc. For instance, a computingdevice may be configured to include a processor and a memory.

In FIG. 12, the processor 1201 may be configured to process computerinstructions and data. The processor 1201 may be configured as anysequential state machine operative to execute machine instructionsstored as machine-readable computer programs in the memory, such as oneor more hardware-implemented state machines (e.g., in discrete logic,FPGA, ASIC, etc.); programmable logic together with appropriatefirmware; one or more stored-program, general-purpose processors, suchas a microprocessor or Digital Signal Processor (DSP), together withappropriate software; or any combination of the above. For example, theprocessor 1201 may include two computer processors. In one definition,data is information in a form suitable for use by a computer. It isimportant to note that a person having ordinary skill in the art willrecognize that the subject matter of this disclosure may be implementedusing various operating systems or combinations of operating systems.

In the current embodiment, the input/output interface 1205 may beconfigured to provide a communication interface to an input device,output device, or input and output device. The configuring node 1200 maybe configured to use an output device via the input/output interface1205. A person of ordinary skill will recognize that an output devicemay use the same type of interface port as an input device. For example,a USB port may be used to provide input to and output from theconfiguring node 1200. The output device may be a speaker, a sound card,a video card, a display, a monitor, a printer, an actuator, an emitter,a smartcard, another output device, or any combination thereof. Theconfiguring node 1200 may be configured to use an input device via theinput/output interface 1205 to allow a user to capture information intothe configuring node 1200. The input device may include a mouse, atrackball, a directional pad, a trackpad, a presence-sensitive inputdevice, a display such as a presence-sensitive display, a scroll wheel,a digital camera, a digital video camera, a web camera, a microphone, asensor, a smartcard, and the like. The presence-sensitive input devicemay include a digital camera, a digital video camera, a web camera, amicrophone, a sensor, or the like to sense input from a user. Thepresence-sensitive input device may be combined with the display to forma presence-sensitive display. Further, the presence-sensitive inputdevice may be coupled to the processor. The sensor may be, for instance,an accelerometer, a gyroscope, a tilt sensor, a force sensor, amagnetometer, an optical sensor, a proximity sensor, another likesensor, or any combination thereof. For example, the input device may bean accelerometer, a magnetometer, a digital camera, a microphone, and anoptical sensor.

In FIG. 12, the RF interface 1209 may be configured to provide acommunication interface to RF components such as a transmitter, areceiver, and an antenna. The network connection interface 1211 may beconfigured to provide a communication interface to a network 1243 a. Thenetwork 1243 a may encompass wired and wireless communication networkssuch as a local-area network (LAN), a wide-area network (WAN), acomputer network, a wireless network, a telecommunications network,another like network or any combination thereof. For example, thenetwork 1243 a may be a Wi-Fi network. The network connection interface1211 may be configured to include a receiver and a transmitter interfaceused to communicate with one or more other nodes over a communicationnetwork according to one or more communication protocols known in theart or that may be developed, such as Ethernet, TCP/IP, SONET, ATM, orthe like. The network connection interface 1211 may implement receiverand transmitter functionality appropriate to the communication networklinks (e.g., optical, electrical, and the like). The transmitter andreceiver functions may share circuit components, software or firmware,or alternatively may be implemented separately.

In this embodiment, the RAM 1217 may be configured to interface via thebus 1202 to the processor 1201 to provide storage or caching of data orcomputer instructions during the execution of software programs such asthe operating system, application programs, and device drivers. In oneexample, the configuring node 1200 may include at least one hundred andtwenty-eight megabytes (128 Mbytes) of RAM. The ROM 1219 may beconfigured to provide computer instructions or data to the processor1201. For example, the ROM 1219 may be configured to be invariantlow-level system code or data for basic system functions such as basicinput and output (I/O), startup, or reception of keystrokes from akeyboard that are stored in a non-volatile memory. The storage medium1221 may be configured to include memory such as RAM, ROM, programmableread-only memory (PROM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), magneticdisks, optical disks, floppy disks, hard disks, removable cartridges,flash drives. In one example, the storage medium 1221 may be configuredto include an operating system 1223, an application program 1225 such asa web browser application, a widget or gadget engine or anotherapplication, and a data file 1227.

In FIG. 12, the processor 1201 may be configured to communicate with anetwork 1243 b using the communication subsystem 1251. The network 1243a and the network 1243 b may be the same network or networks ordifferent network or networks. The communication subsystem 1251 may beconfigured to include one or more transceivers used to communicate withthe network 1243 b. The one or more transceivers may be used tocommunicate with one or more remote transceivers of another configuringnode such as a base station of a radio access network (RAN) according toone or more communication protocols known in the art or that may bedeveloped, such as IEEE 1102.xx, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax,NB-IoT, or the like.

In another example, the communication subsystem 1251 may be configuredto include one or more transceivers used to communicate with one or moreremote transceivers of another configuring node such as user equipmentaccording to one or more communication protocols known in the art orthat may be developed, such as IEEE 1102.xx, CDMA, WCDMA, GSM, LTE,UTRAN, WiMax, NB-IoT, or the like. Each transceiver may include atransmitter 1253 or a receiver 1255 to implement transmitter or receiverfunctionality, respectively, appropriate to the RAN links (e.g.,frequency allocations and the like). Further, the transmitter 1253 andthe receiver 1255 of each transceiver may share circuit components,software or firmware, or alternatively may be implemented separately.

In the current embodiment, the communication functions of thecommunication subsystem 1251 may include data communication, voicecommunication, multimedia communication, short-range communications suchas Bluetooth, near-field communication, location-based communicationsuch as the use of the global positioning system (GPS) to determine alocation, another like communication function, or any combinationthereof. For example, the communication subsystem 1251 may includecellular communication, Wi-Fi communication, Bluetooth communication,and GPS communication. The network 1243 b may encompass wired andwireless communication networks such as a local-area network (LAN), awide-area network (WAN), a computer network, a wireless network, atelecommunications network, another like network or any combinationthereof. For example, the network 1243 b may be a cellular network, aWi-Fi network, and a near-field network. The power source 1213 may beconfigured to provide an alternating current (AC) or direct current (DC)power to components of the configuring node 1200.

In FIG. 12, the storage medium 1221 may be configured to include anumber of physical drive units, such as a redundant array of independentdisks (RAID), a floppy disk drive, a flash memory, a USB flash drive, anexternal hard disk drive, thumb drive, pen drive, key drive, ahigh-density digital versatile disc (HD-DVD) optical disc drive, aninternal hard disk drive, a Blu-Ray optical disc drive, a holographicdigital data storage (HDDS) optical disc drive, an external mini-dualin-line memory module (DIMM) synchronous dynamic random access memory(SDRAM), an external micro-DIMM SDRAM, a smartcard memory such as asubscriber identity module or a removable user identity (SIM/RUIM)module, other memory, or any combination thereof. The storage medium1221 may allow the configuring node 1200 to access computer-executableinstructions, application programs or the like, stored on transitory ornon-transitory memory media, to off-load data, or to upload data. Anarticle of manufacture, such as one utilizing a communication system maybe tangibly embodied in storage medium 1221, which may comprise acomputer-readable medium.

The functionality of the methods described herein may be implemented inone of the components of the configuring node 1200 or partitioned acrossmultiple components of the configuring node 1200. Further, thefunctionality of the methods described herein may be implemented in anycombination of hardware, software or firmware. In one example, thecommunication subsystem 1251 may be configured to include any of thecomponents described herein. Further, the processor 1201 may beconfigured to communicate with any of such components over the bus 1202.In another example, any of such components may be represented by programinstructions stored in memory that when executed by the processor 1201performs the corresponding functions described herein. In anotherexample, the functionality of any of such components may be partitionedbetween the processor 1201 and the communication subsystem 1251. Inanother example, the non-computative-intensive functions of any of suchcomponents may be implemented in software or firmware and thecomputative-intensive functions may be implemented in hardware.

Furthermore, the various aspects described herein may be implementedusing standard programming or engineering techniques to producesoftware, firmware, hardware (e.g., circuits), or any combinationthereof to control a computing device to implement the disclosed subjectmatter. It will be appreciated that some embodiments may be comprised ofone or more generic or specialized processors such as microprocessors,digital signal processors, customized processors and field programmablegate arrays (FPGAs) and unique stored program instructions (includingboth software and firmware) that control the one or more processors toimplement, in conjunction with certain non-processor circuits, some,most, or all of the functions of the methods, devices and systemsdescribed herein. Alternatively, some or all functions could beimplemented by a state machine that has no stored program instructions,or in one or more application specific integrated circuits (ASICs), inwhich each function or some combinations of certain of the functions areimplemented as custom logic circuits. Of course, a combination of thetwo approaches may be used. Further, it is expected that one of ordinaryskill, notwithstanding possibly significant effort and many designchoices motivated by, for example, available time, current technology,and economic considerations, when guided by the concepts and principlesdisclosed herein will be readily capable of generating such softwareinstructions and programs and ICs with minimal experimentation.

The term “article of manufacture” as used herein is intended toencompass a computer program accessible from any computing device,carrier, or media. For example, a computer-readable medium may include:a magnetic storage device such as a hard disk, a floppy disk or amagnetic strip; an optical disk such as a compact disk (CD) or digitalversatile disk (DVD); a smart card; and a flash memory device such as acard, stick or key drive. Additionally, it should be appreciated that acarrier wave may be employed to carry computer-readable electronic dataincluding those used in transmitting and receiving electronic data suchas electronic mail (e-mail) or in accessing a computer network such asthe Internet or a local area network (LAN). Of course, a person ofordinary skill in the art will recognize many modifications may be madeto this configuration without departing from the scope or spirit of thesubject matter of this disclosure.

Throughout the specification and the embodiments, the following termstake at least the meanings explicitly associated herein, unless thecontext clearly dictates otherwise. Relational terms such as “first” and“second,” and the like may be used solely to distinguish one entity oraction from another entity or action without necessarily requiring orimplying any actual such relationship or order between such entities oractions. The term “or” is intended to mean an inclusive “or” unlessspecified otherwise or clear from the context to be directed to anexclusive form. Further, the terms “a,” “an,” and “the” are intended tomean one or more unless specified otherwise or clear from the context tobe directed to a singular form. The term “include” and its various formsare intended to mean including but not limited to. References to “oneembodiment,” “an embodiment,” “example embodiment,” “variousembodiments,” and other like terms indicate that the embodiments of thedisclosed technology so described may include a particular function,feature, structure, or characteristic, but not every embodimentnecessarily includes the particular function, feature, structure, orcharacteristic. Further, repeated use of the phrase “in one embodiment”does not necessarily refer to the same embodiment, although it may. Theterms “substantially,” “essentially,” “approximately,” “about” or anyother version thereof, are defined as being close to as understood byone of ordinary skill in the art, and in one non-limiting embodiment theterm is defined to be within 10%, in another embodiment within 5%, inanother embodiment within 1% and in another embodiment within 0.5%. Adevice or structure that is “configured” in a certain way is configuredin at least that way, but may also be configured in ways that are notlisted.

In view of the above, embodiments herein generally include a method forconfiguring a radio node to transmit, within a guard band for a firstradio access technology (RAT), a radio signal according to a second RAT.The method comprises determining one or more transmit parameters fortransmission of the radio signal according to the second RAT, to complywith emission limits for the first RAT; and configuring the radio nodewith the one or more transmit parameters for transmitting the radiosignal within the guard band of the first RAT.

In some embodiments, said determining is responsive to determining thatthe radio signal is to be transmitted within the guard band for thefirst RAT.

In some embodiments, said determining the one or more transmitparameters comprises adapting, to comply with emission limits for thefirst RAT, the one or more transmit parameters for transmission of theradio signal according to the second RAT.

In some embodiments, said determining the one or more transmitparameters comprises adapting one or more rules according to which theone or more transmit parameters are to be determined, to comply withemission limits for the first RAT.

In some embodiments, said adapting comprises adapting the one or morerules responsive to determining that one or more conditions are metindicating that the adapting is needed for compliance with emissionlimits for the first RAT.

In some embodiments, said determining is performed responsive todetermining that one or more conditions are met indicating thatcompliance with emission limits for the first RAT is required.

In some embodiments, the one or more conditions include that the radiosignal is to be transmitted within the guard band for the first RAT.

In some embodiments, the one or more conditions include that the radiosignal is to be transmitted within a certain frequency region within theguard band for the first RAT.

In some embodiments, the frequency region is a region beyond a definedfrequency offset from an edge of a transmission bandwidth for the firstRAT.

In some embodiments, the frequency region is a region within a definedfrequency offset from an edge of a channel bandwidth for the first RAT.

In some embodiments, the one or more rules impose restrictions on valuesof the one or more transmit parameters, to comply with the emissionlimits for the first RAT.

In some embodiments, said determining is based on a frequency locationof the radio signal within the guard band of the first RAT

In some embodiments, said determining is based on a frequency offsetbetween a carrier frequency of the radio signal within the guard band ofthe first RAT and an edge frequency defining an edge of a transmissionbandwidth of the first RAT.

In some embodiments, said determining the one or more transmitparameters comprises: determining a frequency offset between a carrierfrequency of the radio signal within the guard band of the first RAT andan edge frequency defining an edge of a transmission bandwidth of thefirst RAT; and adapting, based on the frequency offset and to complywith emission limits for the first RAT, the one or more transmitparameters for transmission of the radio signal according to the secondRAT.

In some embodiments, said determining the one or more transmitparameters comprises determining whether to adapt one or more rulesaccording to the one or more transmit parameters.

In some embodiments, said determining whether to adapt the transmitparameters includes: when the frequency offset is less than apredetermined threshold, determining not to perform the step of saidadapting; and when the frequency offset is at least the predeterminedthreshold, determining to perform the step of said adapting.

In some embodiments, said determining whether to adapt the transmitparameters includes: when the frequency offset is less than apredetermined threshold, determining to perform the step of saidadapting; and when the frequency offset is at least the predeterminedthreshold, determining not to perform the step of said adapting.

In some embodiments, said adapting includes: when the frequency offsetis less than a predetermined threshold, adapting the transmit parametersto a first set of transmit parameters; and when the frequency offset isat least the predetermined threshold, adapting the transmit parametersto a second set of transmit parameters.

In some embodiments, one of the first and second set is more restrictivethan the other set on the compliance with emission limits for the firstRAT for the transmission of the radio signal according to the secondRAT.

In some embodiments, said adapting includes restricting, to comply withemission limits for the first RAT, one or more transmit parameters fortransmission of the radio signal according to the second RAT.

In some embodiments, said determining comprises determining the one ormore transmit parameters according to a first set of one or moreconstraints in order to comply with emission limits for the first RAT,responsive to determining that the radio signal is to be transmittedwithin the guard band for the first RAT, wherein the first set of one ormore constraints is different than a second set of one or moreconstraints according to which the radio node is configured to determinethe one or more transmit parameters for transmission of the radio signaloutside the guard band for the first RAT.

In some embodiments, said determining the one or more transmitparameters also complies with emission limits for the second RAT.

In some embodiments, the one or more transmit parameters include afrequency position of the radio signal within the guard band for thefirst RAT.

In some embodiments, the one or more transmit parameters include acarrier frequency on which the radio signal is to be transmitted.

In some embodiments, the one or more transmit parameters include asignal level of the radio signal.

In some embodiments, the one or more transmit parameters include amaximum signal level of the radio signal.

In some embodiments, the one or more transmit parameters include afrequency allocation of subcarriers for the second RAT.

In some embodiments, the one or more transmit parameters include atransport format for the radio signal.

In some embodiments, the transport format includes at least one of amodulation scheme, a coding scheme and a transport block size.

In some embodiments, said determining the transmit parameters includesdetermining a carrier frequency on which the radio signal is to betransmitted according to the second RAT, based on an edge frequencydefining an edge of a transmission bandwidth of the first RAT and adefined frequency offset with respect to that edge frequency.

In some embodiments, said determining the transmit parameters includesdetermining a carrier frequency on which the radio signal is to betransmitted according to the second RAT, to be within a definedfrequency offset from an edge frequency defining an edge of atransmission bandwidth of the first RAT.

In some embodiments, the method further comprises determining thedefined frequency offset based on a channel bandwidth of the first RAT,with defined frequency offsets defined for different possible channelbandwidths of the first RAT.

In some embodiments, the defined frequency offset is specified based onemission requirements for the first RAT.

In some embodiments, the transmit parameters include at least one of anAbsolute Radio Frequency Channel Number (ARFCN) and an offset to achannel raster.

In some embodiments, said determining the transmit parameters includesdetermining the transmit parameters based on at least one of atransmission bandwidth of the first RAT and a channel bandwidth of thefirst RAT.

In some embodiments, said determining the transmit parameters includesdetermining the transmit parameters so that at least one of a spectralemission mask governing transmission of the radio signal according tothe second RAT and a signal level of the radio signal is within aspectral emission mask governing the first RAT.

In some embodiments, the emission limits for the second RAT arespecified to ensure compliance with the emission limits for the firstRAT, and wherein said determining the transmit parameters includesdetermining the transmit parameters for transmission of the radio signalaccording to the second RAT to comply with the emission limits for thesecond RAT.

In some embodiments, the emission limits for the second RAT arespecified as nominal emission limits applicable for transmitting a radiosignal according to the second RAT irrespective of whether the radiosignal is transmitted in the guard band for the first RAT and additionalemission limits applicable in addition to the nominal emission limitsfor transmitting a radio signal according to the second RAT in the guardband for the first RAT.

In some embodiments, the additional emission limits depend on at leastone of a frequency and bandwidth of the radio signal.

In some embodiments, the additional emission limits depend on afrequency offset of the radio signal from an edge frequency defining anedge of a channel bandwidth of the first RAT, with a tighter emissionlimits specified for a smaller frequency offset than a larger frequencyoffset.

In some embodiments, the method further comprises transmitting the radiosignal, according to the second RAT, within the guard band of the firstRAT, in compliance with the emission limits for the first RAT, based onthe one or more transmit parameters.

Embodiments also include a configuring node for configuring a radio nodeto transmit, within a guard band for a first radio access technology(RAT), a radio signal according to a second RAT. The configuring node isconfigured to: determine one or more transmit parameters fortransmission of the radio signal according to the second RAT, to complywith emission limits for the first RAT; and configure the radio nodewith the one or more transmit parameters for transmitting the radiosignal within the guard band of the first RAT.

In some embodiments, the configured node is configured to perform themethod of any of the above embodiments.

Embodiments also include a configuring node for configuring a radio nodeto transmit, within a guard band of a first radio access technology(RAT), a radio signal according to a second RAT. The configuring nodecomprises: a transmit parameter determination circuit configured todetermine one or more transmit parameters for transmission of the radiosignal according to the second RAT, to comply with emission limits forthe first RAT; and a configuration circuit configured to configure theradio node with the one or more transmit parameters for transmitting theradio signal within the guard band of the first RAT.

In some embodiments, the determination circuit includes: a frequencyoffset determination circuit configured to determine a frequency offsetbetween a frequency location of the radio signal within the guard bandof the first RAT and an edge frequency defining an edge of atransmission bandwidth of the first RAT; and an adaptation circuitconfigured to adapt, to comply with emission limits for the first RAT,one or more transmit parameters for transmission of the radio signalaccording to the second RAT based on the frequency offset.

In some embodiments, the configuring node is further configured toconfigure a transmitter configured to transmit the radio signal,according to the second RAT, within the guard band of the first RAT, incompliance with the emission limits for the first RAT, based on the oneor more transmit parameters.

In some embodiments, the configuring node is configured to perform themethod of any of the above embodiments.

In some embodiments, a configuring node for configuring a radio node totransmit, within a guard band of a first radio access technology (RAT),a radio signal according to a second RAT. The configuring node comprisesa transmit parameter determination module for determining one or moretransmit parameters for transmission of the radio signal according tothe second RAT, to comply with emission limits for the first RAT; and aconfiguration module for configuring the radio node with the one or moretransmit parameters for transmitting the radio signal within the guardband of the first RAT.

In some embodiments, the determination circuit includes: a frequencyoffset determination module for determining a frequency offset between afrequency location of the radio signal within the guard band of thefirst RAT and an edge frequency defining an edge of a transmissionbandwidth of the first RAT; and an adaptation module for adapting, tocomply with emission limits for the first RAT, one or more transmitparameters for transmission of the radio signal according to the secondRAT based on the frequency offset.

In some embodiments, the configuring node further comprises atransmission module configured to transmit the radio signal, accordingto the second RAT, within the guard band of the first RAT, in compliancewith the emission limits for the first RAT, based on the one or moretransmit parameters.

In some embodiments, the configured node is configured to perform themethod of any of the above.

Other embodiments include a configuring node for configuring a radionode to transmit, within a guard band for a first radio accesstechnology (RAT), a radio signal according to a second RAT. Theconfiguring node comprises a processor and a memory, the memorycontaining instructions executable by the processor whereby theconfiguring node is configured to: determine one or more transmitparameters for transmission of the radio signal according to the secondRAT, to comply with emission limits for the first RAT; and configure theradio node with the one or more transmit parameters for transmitting theradio signal within the guard band of the first RAT.

In some embodiments, the memory contains instructions executable by theprocessor whereby the configuring node is configured to perform themethod of any of the above embodiments.

Embodiments further include a computer program, comprising instructionswhich, when executed on at least one processor of a configuring node,cause the at least one processor to carry out the method according toany of the embodiments.

Embodiments further include a carrier containing the computer program,wherein the carrier is one of an electronic signal, optical signal,radio signal, or computer readable storage medium.

What is claimed is:
 1. A method for configuring a radio node (705, 711) to transmit, within a guard band of a first radio access technology, RAT, a radio signal (709) according to a second RAT, the method comprising: configuring the radio node to transmit the radio signal according to the second RAT within the guard band of the first RAT, wherein the transmission is based on a channel bandwidth of the first RAT and emission limits for the first RAT.
 2. The method of claim 1 wherein configuring the radio node to transmit the radio signal according to the second RAT within the guard band of the first RAT comprises configuring one or more transmit parameters for transmitting the radio signal.
 3. The method of claim 2, wherein: the one or more transmit parameters include a carrier frequency on which the radio signal is to be transmitted according to the second RAT; and the carrier frequency is determined based on an edge frequency defining an edge of the channel bandwidth of the first RAT and a defined frequency offset with respect to the edge frequency.
 4. The method of claim 3, further comprising determining the defined frequency offset based on the channel bandwidth of the first RAT, with defined frequency offsets defined for different possible channel bandwidths of the first RAT.
 5. The method of claim 3, wherein the defined frequency offset is specified based on emission requirements for the first RAT.
 6. The method of claim 2, wherein: the one or more transmit parameters include the frequency position of the radio signal; and the frequency position is determined such that a spectral emission mask governing transmission of the radio signal according to the second RAT is within a spectral emission mask governing the first RAT.
 7. The method of claim 1, wherein: nominal emission limits are applicable for transmitting a radio signal according to the second RAT irrespective of whether the radio signal is transmitted in the guard band for the first RAT; additional emission limits are applicable in addition to the nominal emission limits for transmitting a radio signal according to the second RAT in the guard band for the first RAT, depending on a frequency offset of the radio signal (709) from an edge of a channel bandwidth (731) for the first RAT; and wherein the additional emission limits are enforced when the frequency offset is smaller than a defined threshold and are not enforced when the frequency offset is greater than the defined threshold.
 8. The method of claim 7, wherein the defined threshold depends on a size of the channel bandwidth for the first RAT.
 9. The method of claim 2: wherein a spectrum emission mask for the second RAT applies to frequencies starting from an edge of a channel bandwidth of the second RAT; and wherein the determining comprises determining the frequency position based on requirements specified for the spectrum emission mask for the second RAT regarding an offset frequency from an edge of the channel bandwidth of the first RAT.
 10. The method of claim 9, wherein the offset frequency depends on a size of the channel bandwidth of the first RAT.
 11. The method of claim 9, wherein: the one or more transmit parameters include a carrier frequency on which the radio signal is to be transmitted according to the second RAT; and the frequency position is determined based on a table that specifies respective offset frequencies required for different possible sizes of the channel bandwidth of the first RAT.
 12. The method of claim 2, wherein: the one or more transmit parameters include a carrier frequency on which the radio signal is to be transmitted according to the second RAT; and the frequency position is determined based a requirement of at least a certain frequency offset between an edge of the channel bandwidth of the first RAT and an edge of a channel bandwidth of the second RAT.
 13. The method of claim 12, wherein the certain frequency offset required depends on a size of the channel bandwidth of the first RAT.
 14. The method of claim 2, wherein the determining comprises determining the frequency position based on a requirement regarding an offset frequency from an edge of the channel bandwidth of the first RAT.
 15. The method of claim 2, wherein the determining comprises determining the one or more transmit parameters for transmission of the radio signal to comply with emission limits for both the first and second RATs.
 16. The method of claim 1 wherein: the method is performed by a base station; and the method further comprises transmitting the one or more transmit parameters to the radio node.
 17. The method of claim 1 wherein: the method is performed by a user equipment; and the method further comprises transmitting the radio signal as configured with the one or more transmit parameters.
 18. A radio node for transmitting, within a guard band for a first radio access technology (RAT), a radio signal according to a second RAT, the user equipment comprising: processing circuitry for determining one or more transmit parameters for transmitting the radio signal according to the second RAT within the guard band of the first RAT, wherein the transmission is based on a channel bandwidth of the first RAT and emission limits for the first RAT. radio circuitry for transmitting the radio signal or the one or more transmit parameters to a second radio node.
 19. The radio node of claim 18 wherein the radio node comprises a base station configured to transmit the transmit parameters to user equipment.
 20. The radio node of claim 18 wherein the radio node comprises a user equipment configured to transmit the radio signal. 